Thousands of Facebook users have fallen for a competition promoted by a fake Jetstar page, promising 200 free airfares (five each for 40 people) and five-star accommodation for two weeks in Fiji, with $4500 in spending money.

To enter, the page claimed, all users had to do was like and share the photo posted on the page.

The ploy worked, with the page receiving more than 18,000 'likes' from Facebook users in less than 24 hours. A limited timeframe may have helped, with a claim that the competition would close on July 3.

Telltale signs the page was fake failed to deter thousands of hopefuls. Firstly, the page contained no other content beyond the competition. Jetstar's real Facebook page, which was created in September 2010, has more than 330,000 'likes' and hundreds of posts. Secondly, the competition, which in spending money alone would cost the airline $180,000, on top of the airfare and accommodation costs, is simply too good to be true.

In a statement, Jetstar said no major Australian airline has been immune from these types of scams and it was expected this type of behaviour would continue.

The airline said all fake Jetstar social media accounts are reported.

"We have heard reports of some customers liking or sharing fake Jetstar Australia Facebook posts but no reports of accounts being compromised," the airline said.

The airline advised users to look at the tips found on the Australian Competition and Consumer Commissions SCAMWatch website.

The purpose of these fake pages is typically to engage in 'like farming' according to scam watchdog site Hoax-slayer.com.

"The intention of these scammer like-farmers is to increase the value of the bogus Facebook Pages they create so that they can be sold on the black market to other scammers and/or used to market dubious products and services and distribute further scams. The more likes a Page has, the more resale and marketing value it commands," the website states.

Airlines have become common targets for internet scams in recent years, with Australian airline brands being used in fake email itineraries aimed at spreading viruses and malware. Other airlines have also been targeted with fake accounts on Instagram.